The domestic Pressurized Heavy Water Reactor (PWHR) nuclear power plant, Wolsong Unit 1, was permanently shut down on December 24, 2019. However, research on decommissioning has mainly focused on Pressurized Water Reactors (PWRs), with a notable absence of both domestic and international experience in the decommissioning of PHWRs. If proper business management such as radiation safety and waste is not performed, it can lead to increased business risks and costs in decommissioning. Therefore, the assessment of waste volume and cost, which provide fundamental data for the nuclear decommissioning process, is a crucial technical requirement before initiating the actual decommissioning of Wolsong Unit 1. Decommissioning radiation-contaminated structures and facilities presents significant challenges due to high radiation levels, making it difficult for workers to access these areas. Therefore, technology development should precede decommissioning process assessments and safety evaluations, facilitating the derivation of optimal decommissioning procedures and ensuring worker safety while enhancing the efficiency of decommissioning operations. In this study, we have developed a program to estimate decommissioning waste amounts for PHWRs, building upon prior research on PWR decommissioning projects while accounting for the specific design characteristics of PHWRs. To evaluate the amount of radioactive waste generated during decommissioning, we considered the characteristics of radioactive waste, disposal methods, packaging container specifications, and the criteria for the transfer of radioactive waste to disposal operators. Based on the derived algorithm, we conducted a detailed design and implemented the program. The proposed program is based on 3D modeling of the decommissioning components and the calculation of the Work Difficulty Factor (WDF), which is used to determine the time weighting factors for each task. Program users can select the cutting and packaging conditions for decommissioning components, estimate waste amount based on the chosen decommissioning method, and calculate costs using time weighting factors. It can be applied not only to PHWRs, but also to PWRs and non-nuclear fields, providing a flexible tool for optimizing decommissioning process.

It has been known that as oxide layer (ZrO2) forms on the nuclear fuel cladding during irradiation in nuclear power plants, the corrosion kinetics are influenced by various parameters such as chemical environments. One of those environments, crud deposition driven by coolant chemistry has an adverse effect on the formation of oxide (ZrO2) and leads to increase thickness of the layer. In this study, crud formation was performed through loop experiment equipment on the surface of intentionally-made oxide layer (ZrO2) on cladding tubes and then the composition and characteristics of cruds were examined for the investigation of nuclear power plant environment. As a result, various cruds in composition and microstructure were formed depending on the exquisite methods and conditions such as metal ion concentration.

With the aging of nuclear power plants (NPPs) in 37 countries around the world, 207 out of 437 NPPs have been permanently shutdown as of August 2022 according to the IAEA. In Korea, the decommissioning of NPPs is emerging as a challenge due to the permanent shutdown of Kori Unit 1 and Wolsong Unit 1. However, there are no cases of decommissioning activities for Heavy Water Reactor (HWR) such as Wolsong Unit 1 although most of the decommissioning technologies for Light Water Reactor (LWR) such as Kori Unit 1 have been developed and there are cases of overseas decommissioning activities. This study shows the development of a decommissioning waste amount/cost/process linkage program for decommissioning Pressurized Heavy Water Reactor (PHWR), i.e. CANDU NPPs. The proposed program is an integrated management program that can derive optimal processes from an economic and safety perspective when decommissioning PHWR based on 3D modeling of the structures and digital mock-up system that links the characteristic data of PHWR, equipment and construction methods. This program can be used to simulate the nuclear decommissioning activities in a virtual space in three dimensions, and to evaluate the decommissioning operation characteristics, waste amount, cost, and exposure dose to worker. In order to verify the results, our methods for calculating optimal decommissioning quantity, which are closely related to radiological impact on workers and cost reduction during decommissioning, were compared with the methods of the foreign specialized institution (NAGRA). The optimal decommissioning quantity can be calculated by classifying the radioactivity level through MCNP modeling of waste, investigating domestic disposal containers, and selecting cutting sizes, so that costs can be reduced according to the final disposal waste reduction. As the target waste to be decommissioning for comparative study with NAGRA, the calandria in PHWR was modeled using MCNP. For packaging waste container, NAGRA selected three (P2A, P3, MOSAIK), and we selected two (P2A, P3) and compared them. It is intended to develop an integrated management program to derive the optimal process for decommissioning PHWR by linking the optimal decommissioning quantity calculation methodology with the detailed studies on exposure dose to worker, decommissioning order, difficulty of work, and cost evaluation. As a result, it is considered that it can be used not only for PHWR but also for other types of NPPs decommissioning in the future to derive optimal results such as worker safety and cost reduction.

The purpose of this study was to determine the effects of heat appli˗ cation on the immune activities of the human body. To exam, further˗ more, the immune effect from the healthy volunteer(male:15, female:15) by monitoring changes of immune substances such as various leukocytes[total white blood cell(WBC), eosinophil, neutrophil, basophil, monocyte, and lymphocyte], a comparative study with warm water immersion(40.8±0.3℃) and infrared(250W) was carried out. The plasma analysis showed that the count of white blood cell, eosinophil, and neutrophil were elevated in warm water immersion- or infrared˗ stimulated group compared with control group. However, the count of basophil was decreased in both warm water immersion- and infrared-stimulated group than control group. Therefore, these results suggest that the thermostimulation improved immune activity.

The purpose of this study is to find out how SNS marketing activities affect brand recognition, brand familiarity, and purchase intention for consumers who have purchased products from franchise chicken stores, including whether there is a moderating effect according to gender. SNS marketing activities were set up by configuring three attributes which are, SNS advertising, SNS information, and SNS events as sub-factors. For empirical analysis, a survey was conducted on SNS users, and SPSS/AMOS statistical programs were employed for the data analysis. First, the result of the empirical analysis showed that SNS advertising, SNS information, and SNS events have a significant positive effect on brand recognition. Second, it was found that the SNS events had a significant positive effect on brand familiarity. Third, it was found that SNS advertising has a significant positive effect on purchase intention. Fourth, it was observed that brand recognition has a significant positive effect on brand familiarity. Fifth, it was found that brand recognition and brand familiarity have a significant positive effect on purchase intention. Sixth, it was found that gender plays a significant role in the relationship between these constructs. Therefore, it can be assumed that the hypothesis presented in this study is sufficiently proven.

Background : Astragalus membranaceus is one of the most widely used traditional medicinal herbs in Korea. Studies on the genomic of A. membranaceus resources have not been carried out so far. The present study was carried out to discriminate A. membranaceus based on genetic diversity using genomic simple sequence repeat (SSR) markers. Methods and Results : We collected 5 A. membranaceus lines: Asung, Poongsung, Am-Jecheon, Am-Sancheong, and Am-China. One hundred mg of fresh leaves were used for genomic DNA extraction using the DNeasy plant DNA isolation kit (Qiagen GmbH, Hilden, Germany). 450,449 contigs were searched for 147,766 SSR candidate loci in this study using the MicroSAtellite identification tool (MISA). We selected 949 A. membranaceus genomic SSR markers that were showed variation for the five collections in silico screening with CLC genomics workbench program. The genetic diversity of all A. membranaceus resources was analyzed using 17 SSR markers employing the DNA fragment analysis method. Based on the genetic diversity analysis, these lines were classified into four distinct groups. Conclusion : These findings could be used for further research on cultivar development using molecular breeding techniques and for conservation of the genetic diversity of A. membranaceus. Furthermore, the markers could be used for marker-assisted selection for crop breeding.

Herb extracts commercially used in Korea were screened for PPAR-γ agonist test and α-glucosidase inhibition assay. Total 16 herb plants had a PPAR-γ agonist activity. Specially, Alisma orientale Juz (108.41%), Ephedra sinica (98.22%), Sasa japonica Makino var. purpurascens Nakai (140.68%), Astragalus membranaceus Bunge (106.79%) and Cnidium officinale Makino (113.00%) showed high PPAR-γ agonist activity rate compared with rosiglitazone's (167.46%). And Cornus officinalis S. et Z. (90.3%), Cinnamomum cassia Blume (89.2%), Psoralea corylifolia L. (89.8%), Paeonia japonica (Makino) Miyabe (92.4%) and Paeonia suffruticosa Andr (93.2%), showed high α-glucosidase inhibition rates. These results support previous reports of the efficacy of Oriental medicinal plants used for diabetes mellitus.

The pollen grain is a unique tricellular structure suitable for the delivery of the sperm cells to the ovule. All nutrients required for microspore and pollen cell growth are derived by passage through the anther locule and secretion by the tapetum lining. During later stages the tapetum degenerates but contributes to produce pigments, waxes, lipids and proteins which form the pollen coat and function in signaling between male (pollen) and female (pistil) tissues. The development of both normal pollen and tapetum is necessary for the fertilization processes in rice and would be exploited for the induction of male-sterility which is very useful to improve economic value of crops. We aredeveloping new approaches using a conditional male-sterility for the F1 hybrid seed production in rice. The conventional three parental systems for F1 hybrid seed production requirethe following three lines: male-sterile line, maintainer line, and restorer line. In this system, a critical requirement is to maintain the male-sterile inbred lines. Here we suggest molecular approaches, in which the engineered male-sterile plants are generated by regulating endogenous hormonal balance through the loss-of-function of genes. We can expect the male-sterility can be restored by exogenous applications of hormones such as gibberellin or jasmonic acid. Based on two parental systems, we will address the answer onfollowing question: how can we maintain a male-sterile line producing 100% male-sterile progenies without a maintainer? This work was supported by grants from Crop Functional Genomics Center of the 21C Frontier Program (CG1517), RepublicKorea.

A new soybean cultivar for soy-paste, “Mansu”, was developed from the cross between ‘Suwon 192’, which was tolerant to disease, late maturing and high yielding, and ‘Suwon 196’ which was early maturing and large seed by soybean breeding team in the Yeongnam Agricultural Research Institute (YARI) to make new variety having large seed and high yielding. A promising line, SS97213-2B-3SSD-39-1-1, was selected and designated as the name of ‘Suwon 236’. It was characterized by regional yield trials (RYT) for three years from 2004 to 2006 and released as the name of “Mansu”. It has a determinate growth habit, purple flower, grey pubescence, pale green seed coat, yellow cotyledon, large spherical seed (26.5 grams per 100 seeds). Maturity date is 4 days later than the check cultivar, Taekwang. The average yield of Mansu was 2.93 ton per hectare in the regional yield trials (RYT) carried out for three years from 2004 to 2006 which was 7 percent higher than that of the check cultivar, Taekwang.